Absorption of Electromagnetic Energy While Keeping Heat at Bay

A team of electrical engineers working at the Duke University recently came up with world’s first electromagnetic metamaterial that is devoid of any metal. This makes this device capable of absorbing electromagnetic energy without heating up. This innovation will find huge application in the field of lighting, sensing, and imaging. Metamaterials can be termed as those synthetic materials that are made from multiple single well-designed features that can together generate the properties that cannot be found in nature. Just imagine an electromagnetic wave that is passing from one flat surface that is formed of thousands of electrical cells. If researchers are able to tune up every single cell that can manipulate every wave in a specific manner, these will be able to dictate the wave behaviour as a whole in a precise manner.

The researchers had to make use of electrically conducting metals to manipulate electromagnetic waves. This approach led to a basic issue with metals – more than required electrical conductivity which also conducted heat. This restricted their use in temperature dependent applications. I a recently published paper, the team of electrical engineers working at the Duke University showcased their first completely dielectric electromagnetic metamaterial which looks like a surface filled with cylindrical faced Lego bricks that have been designed to absorb terahertz waves. However, in this specific aspect, the frequency falls between infrared and microwaves, but this approach is flexible enough to include any measure of frequency in an electromagnetic spectrum.

A professor in electrical and computer engineering at the Duke University, Willie Padilla, adds, “People have created these types of devices before, but previous attempts with dielectrics have always been paired with at least some metal. We still need to optimize the technology, but the path forward to several applications is much easier than with metal-based approaches.”